Recoil resolution of precipitates under particle irradiations

Computer simulation calculations have been carried out for precipitate recoil resolution under energetic particle irradiatons. Using MARLOWE code, recoil range distribution in complete cascade events is calculated. From this result, precipitate shrink rate is derived in various irradiation conditions. The resolution rate is found to be highly sensitive to projectile mass rather than projectile energy. This suggests a considerable difference of resolution rate under heavy and light ion irradiations. Remarkable change of precipitate size begins only after irradiation to several tens dpa. This implies that heavy irradiation can rearrange the precipitates which are stable at low doses. Comparing with fission neutron irradiation data, it is shown that recoil resolution of tiny but numerous precipitates can be a factor to determine the incubation dose of void swelling. (author)